A FOIA officer in Texas accepted a request for “Any record or document that shows the dates of employment and/or current employment status of [a guy I was researching] in the Texas Army National Guard” and fulfilled with a screenshot of an HR software screen showing the rank and dates of service.

It wasn’t comprehensive, but there was no requirement for getting a signature, date of birth, or SSN.

Regarding your question on the FOI listserv, there is another source, though not as definitive as the NPRC, that also may be of interest. Doug Sterner uses FOIA daily to obtain official military medal citations from NPRC. A Vietnam veteran, he has uncovered hundreds of cases of falsified military valor in his compilation of a database of more than 200,000 military honor citations.